«Abstract As a consequence of a variety of geo-political and technical developments, we are currently witnessing an increasing commitment to renewable ...»
A GIS-based Concept for Solar Energetic Examination
of New Building Projects
GIS-gestütztes Konzept zur solarenergetischen Prüfung von
Mareike SCHOOF, Bernd RESCH, Dorothea LUDWIG
Mareike Schoof, IP SYSCON GmbH Osnabrück, Möserstraße 1, 49074 Osnabrück,
Bernd Resch, Universität Heidelberg, Berliner Straße 48, 69120 Heidelberg,
Dorothea Ludwig, IP SYSCON GmbH Osnabrück, Möserstraße 1, 49074 Osnabrück, email@example.com Abstract As a consequence of a variety of geo-political and technical developments, we are currently witnessing an increasing commitment to renewable energy sources. In effect, communes react to these developments by undertaking solar energetic examinations of new building projects. However, current research solely focuses on solar potential assessment for existing structures. Furthermore, available software solutions do not consider relevant factors for decentralised energy generation right at the start of the analysis and planning procedures of new buildings and urban areas. This paper presents a concept for solar energetic examination of new building projects with special regard to communes’ needs. In a first step, we examined the particular requirements in communes. Then, we created a holistic GIS-based concept for supporting the planning process of new building projects and validated it in a prototypical realisation. Our results show that GIS is likely to be a linking element between different parties involved into the planning process for new building projects (not only for existing structures) such communal planners, infrastructure operators, energy producers and political decision makers.
Zusammenfassung Die verstärkte Nutzung erneuerbarer Energien ist vor dem Hintergrund der Energiewende ein aktuelles Thema. Die Kommunen reagieren auf diese Entwicklungen und führen zunehmend solarenergetische Prüfungen von Neubauvorhaben durch. Aktuelle Untersuchungen beschäftigen sich jedoch lediglich mit Solarpotenzialanalysen für bestehende Strukturen. Außerdem berücksichtigen vorhandene Softwarelösungen die Schoof, Resch, Ludwig relevanten Faktoren für eine dezentralisierte Energiebereitstellung nicht direkt zu Beginn der Planung von neuen Gebäuden und städtebaulichen Entwürfen. Dieser Artikel stellt deshalb ein Konzept zur solarenergetischen Prüfung von Neubauvorhaben unter besonderer Berücksichtigung der Bedürfnisse der Kommunen vor. Zunächst werden die Anforderungen in den Kommunen untersucht. Auf dieser Basis erfolgen die Erstellung eines GIS-gestützten Konzepts zur Unterstützung des Planungsprozesses sowie eine Validierung anhand einer prototypischen Umsetzung. Die Ergebnisse zeigen, dass GIS als Bindeglied zwischen verschiedenen am Planungsprozess beteiligten Akteuren, wie Kommunalplanern, Infrastrukturbetreibern, Energieerzeugern und politischen Entscheidungsträgern, dienen kann (nicht nur für bestehende Strukturen).
Solar energetic examination, planning, renewable energies, GIS Solarenergetische Prüfung, Solare Bauleitplanung, Erneuerbare Energien, GIS 1 Introduction As a consequence of a variety of geo-political and technical developments, we are currently witnessing an increasing commitment to renewable energy sources. Particularly in Germany, the percentage of renewable energy has increased significantly over the last years, mostly due to the Renewable Energy Law (Erneuerbare-Energien-Gesetz – EEG) (BMWI; BMU 2012).
This focus has two far-reaching consequences: First, from a consumer viewpoint, lower consumption of energy and thus a reduction of energy-related expenses play an important role. Second, at the same time, many people are becoming more environmentally conscious and want to live in a more sustainable way (UMWELTBUNDESAMT 2008). They are well aware that they can actively contribute to a transition in energy production and usage from fossil fuels and nuclear energy to renewable sources by using solar energy.
In effect, communes are currently starting to react to these developments by undertaking solar energetic examinations of new building projects (STADT AUGSBURG 2007, ENERGIEAGENTUR.NRW 2011). Most current approaches solely focus on using existing infrastructure for decentralised energy generation, for instance, by actively harvesting energy from solar panels mounted on commercial and residential buildings’ roofs. Thus, new building projects are neglected in most cases in solar potential analysis.
However, relevant factors for decentralised energy generation and savings need to be considered right at the start of the analysis and planning of new buildings and urban areas.
The aims of solar energetic urban planning are 1.) increasing use of renewable energies and 2.) passive as well as active energy savings. Relevant factors are building’s compactness and orientation, the slope of the roof surface, shading, improved heat protection, and efficient energy supply. Optimising these parameters can lead to lower heating requirements (GORETZKI 1998).
By considering the above mentioned factors, energy-efficient architecture can be integrated into an urban development process. Yet, existing analysis software is mostly inadequate and not sufficiently developed. This means that suitable software tools, which enable an automatic analysis and planning, are missing.
A GIS-based Concept for Solar Energetic Examination of New Building Projects 3 This paper presents a concept for solar energetic examination of new building projects with special regard to communes’ needs. Our work contrasts or extends previous work in two ways: first, by considering new building projects instead of existing built structures; and second, by focusing on urban planning processes rather than on individual buildings.
The methodology of the research presented within this paper is as follows. In a first step, we examined the particular requirements in communes and their actual need for solar potential planning tools. For this purpose, we developed a questionnaire, which focuses on assessing the requirements for the use of Geographic Information Systems (GIS) based software for planning new buildings and urban areas under thorough consideration of solar energetic aspects.
On the basis of the survey results, we developed a GIS-based software concept to support the growing need for leveraging renewable energies, which in turn requires consideration of numerous small, regionally spread energy sources. Our results show that GIS can potentially be a linking element between different participants like communal planners, infrastructure operators, energy producers and political decision makers.
This paper is structured as follows: This introduction is followed by a section on related work. Thereafter, we elaborate on our methodology and requirements analysis in section 3.
The concept is presented in section 4 and is followed by the results of the practical realisation in section 5. Finally we give a conclusion.
2 Related Work We are currently witnessing an increasing commitment to renewable energy sources. The acquisition and provision of energy information are important aspects in the process of energy transition, which communes are bound to by the Geodata Access Act (Geodatenzugangsgesetz) (KOMMUNALES KOORDINIERUNGSGREMIUM GDI-DE 2013).
Up to now, communes often use solar potential cadastres for existing buildings (BRÜCKNER & LAKES 2012). However, climate protection is also increasingly integrated in urban planning. Various communes have already made approaches for energy savings and CO 2 reductions by using solar energy. Examples include STADT AUGSBURG 2007 and ENERGIEAGENTUR.NRW 2011. In the 1990s, GORETZKI 1998 already developed paperbased templates as well as a software programme as tools to support solar energetic urban planning.
Regarding the energy transition to renewable energy sources it is important to develop new supply concepts. Decentralised as well as centralised approaches like smart grids and super grids are possible, which can also be combined with each other (KROPP 2010).
SÚRI & HOFIERKA 2004 developed a process that generally deals with solar radiation analysis using the GRASS GIS function r.sun. Furthermore, there are different methods for calculating the incident radiation for building facades from CARNEIRO ET AL. 2009, JOCHEM ET AL. 2011, HÖFLE 2012 or HÖFLE & JOCHEM 2012 on the basis of laser scanning data.
The current approaches focus on existing building structures on the basis of laser scanning data. In contrast, this paper deals with new building projects. The building facades’ position Schoof, Resch, Ludwig and aspect are known as the buildings are planned and modelled by ourselves. Thus, laser scanning data is not required. Nevertheless, point based methods are also conceivable for solar radiation analysis. This work analyses and shows the possibilities of a GIS-based realisation. This is especially important as it deals with a spatial question and the methods for solar radiation analysis are based on GIS functions.
3 Requirements Analysis for Solar Energetic Examinations of New Building Projects For assessing communes’ needs in terms of solar energetic planning of new buildings and urban areas, we designed a questionnaire containing ten questions. On the one hand side, they deal with tools and programmes that are already used for solar energetic examinations, their possible deficits and their frequency of use. On the other hand side, the requirements for future software, the use of GIS as well as legal frames and regulations that have to be observed, are queried.
The questionnaire has been realised using the online service SoSci Survey (SOSCI SURVEY 2012). The evaluation has been performed by using the statistical software SPSS (IBM SPSS STATISTICS 2012). Altogether, about 300 communes were surveyed, of which on average of 73 answered the questions.
This section presents the results of the user study. The result discussion and interpretation for each question are done in sub-section 3.1 separately for every question, whereas an overall discussion and conclusion for the survey are presented in sub-section 3.2.
3.1 User Study Question 1 asked whether a commune already performs solar energetic examinations for new building projects (yes/no). Only 18.4% (18 out of 98) of the surveyed communes answered this question with “yes”. This low number is quite surprising – even though the authors expected a rather low percentage – as a higher number would have been perfectly plausible considering the ongoing public debate subsumed under the term “energy transformation”. Yet, this low percentage clearly underpins the need of the performed survey and the research presented within this paper.
Question 2 asked, which tools and programmes communes are currently using for solar energetic examination of new building projects. Participants could specify up to five tools and programmes in free-text answers. Some communes are using a specialised software tool and some even still execute a manual analysis of the planning using paper-based templates. This again shows the necessity for fostering communes’ awareness for the opportunities of using GIS-based analysis software in planning new building projects.
Question 3 asked about the usability of currently used tools and programmes. Answering possibilities were pre-defined: “very good”, “good”, “acceptable”, “rather bad”, “bad”. The usability of the specialised software programme GOSOL is only rated as “acceptable” because the programme’s handling, data output and transfer are difficult. A major disadvantage is that it works at DOS level, so that the compatibility with other programmes A GIS-based Concept for Solar Energetic Examination of New Building Projects 5 and data formats cannot be guaranteed. On the other hand, the manual analysis is rated as “good”.
Question 4 asked to specify deficits of these currently used tools and programmes. To make the question easily understandable to all test persons, who potentially have heterogeneous educational backgrounds and knowledge bases, a few possible criteria such as map portrayal, functionality, integration with other systems, supported data formats, etc.
were given. The specialised software programme is criticised mainly because of its data output, the integration with other systems as well as the layout of resulting maps. The manual analysis is rated as not accurate enough.
Question 5 asked how often the available tools and programmes are used. Four out of six communes undertake solar examinations at every planning or often, two only at times.
Question 6 asked whether communes consider software for supporting planning processes in solar energetic examinations of new building projects useful. The question was asked in a yes-no fashion with an additional possibility of giving free-text comments. 58.9% (43 out of 73) of the communes regard such software as practical and helpful. The free-text answers show that the focus should not be set on individual construction projects, but on urban planning. A newly developed software tool should provide functions for calculating the passive solar potential, the reasons for reduced solar gains (e.g. unfavourable orientation or shading) and the examination of incident radiation according to DIN 5034 (German norm for daylight in interiors) and possibly determination of the active solar potential.
Question 7 asked whether communes are already using Geographic Information Systems (GIS). Additionally to a yes-no choice, participants were asked to name the GIS tools they are currently using. Regarding the GIS-based concept, which is to be developed, it is remarkable that 97.3% (72 out of 74) of the communes already have experience in using Geographic Information Systems. ArcGIS is the most frequently used GIS software tool.
Question 8 asked, which legal regulations communes need to comply with when performing solar energetic examinations. The free-text answers concerning these laws and regulations comprise the German Building Code (Baugesetzbuch – BauGB) and the corresponding building codes of the individual federal states, the Renewable Energy Heat Act (Erneuerbare-Energien-Wärmegesetz – EEWärmeG) as well as the Energy Saving Ordinance (Energieeinsparverordnung – EnEV). In addition, some communes have established their own directives, design statutes or determinations in land use plans.